1. Field of the Invention
The present invention relates to an apparatus and a method for processing a code related to user information.
2. Description of the Related Art
A security level of a paper document is lower than that of a data file. For improving the security level of a paper document, the technology for printing user information identifying who produced the paper document is applied. In doing so, the paper document is not to be hand out indiscriminately.
Japanese Patent Laid-Open Application No. 2010-136098 (hereinafter '098) discloses a multi functional printer (MFP) printing a code including two areas (but not three or more). The each area may include user information. One of the two areas is called the original user information area. The other is called the latest user information area.
In '098, the code is generated by encoding code information including two blocks where one is called an original user information block and the other is called a latest user information block. The original user information block corresponds to the original user information area, and the latest user information block corresponds to the latest user information area.
FIG. 2 represents the generated code information. Code information 201 is generated when A instructs printing. Code information 202 is generated when B instructs copying. Code information 203 is generated when C instructs copying.
In details, when the MFP prints document by the instruction of A, the MFP generates the code information 201 including user information identifying who instructs the printing (i.e. A) in the original user information block and no user information in the latest user information block. And then, the MFP generates a code by encoding the code information 201. Finally, the MFP synthesizes the code and the document, and prints the synthesized result to produce a paper document.
When the MFP copies the paper document by the instruction of B, the MFP captures (e.g., scans) the image of the paper document, deletes the code from the captured image and generates a new code information 202 including the same user information (i.e. A) in the original user information block and user information (i.e. B) identifying who instructs the copying in the latest user information block. Thereafter, the MFP generates a new code by encoding the new code information 202. Finally, the MFP synthesizes the new code and the captured image, and prints the new synthesized result to produce a renewed paper document.
When the MFP copies the renewed paper document by the instruction of C, the MFP captures the image of the renewed paper document, and deletes the new code from the captured image and generates another new code information 203 including the same user information (i.e. A) in the original user information block and user information identifying who instructs copying this time (i.e. C) in the latest user information block. Thereafter, the MFP generates another new code by encoding the other new code information 203. Finally, the MFP synthesizes the other new code and the captured image, and prints the synthesized result to produce a further renewed paper document.
In this way, the MFP prints a code including the oldest user information such as A in the original user information area and the latest user information such as C in the latest user information area.
However, the application does not disclose the case where the MFP copies a paper document including no information in the original user information area and also no information in the latest user information area (see the (I)'s obtained code information in FIG. 4).
Also, the application does not disclose the case where the MFP copies a paper document including no information in the original user information area but some information in the latest user information area (see the (II)'s obtained code information in FIG. 4).